- In the pursuit of the enemy. A single corps as advanced guard, with the greater part of the cavalry attached to it, can move quicker, arriving later at its bivouac, and moving earlier in the morning than the whole mass.
Lastly, on a retreat, as rearguard, to be used in defending the principal natural obstacles of ground. In this respect also the centre is exceedingly important. At first sight it certainly appears as if such a rearguard would be constantly in danger of having its flanks turned. But we must remember that, even if the enemy succeeds in overlapping the flanks to some extent, he has still to march the whole way from there to the centre before he can seriously threaten the central mass, which gives time to the rearguard of the centre to prolong its resistance, and remain in rear somewhat longer. On the other hand, the situation becomes at once critical if the centre falls back quicker than the wings; there is immediately an appearance as if the line had been broken through, and even the very idea or appearance of that is to be dreaded. At no time is there a greater necessity for concentration and holding together, and at